We're so sorry that you forgot to add your VAT number to your purchase! We, unfortunately, cannot refund just the VAT charge, but what we can do is refund the entire purchase for you. Once this has been done, we can organize a manual payment without the VAT charge and send you a customized invoice for your purchase. If you'd like to go ahead with this, please email us with your order number and VAT number and we'd be happy to help.
Alternatively, we can just add your VAT number to your invoice so that you can claim this back at a later date!